Quinoline Derivatives. XIV. Chemistry of 2-(Phenylamino)-lepidine Derivatives

Reaction of 2-anilinolepidine with 1.2 mole of nitric acid in acetic acid at room temperature afforded only a mononitrate (VIII). Dissolution of VIII into 98% sulfuric acid under ice chilling afforded 2-(o-nitroanilino) lepidine (I), 2-(p-nitroanilino) lepidine (III), and 2-(p-nitroanilino)-6-nitrolepidine (V). Reaction of VII with acetyl nitrate in dichloromethane at room temperature for 3 hr afforded I in 75% yield, while prolongation reaction time to 15 hr afforded 2-(2', 4'-dinitroanilino) lepidine (IV) in 95% yield. III was obtained by reaction of VII with a large excess of nitric acid. These reaction are optimal for the selective nitration of the anilino group of VII, in order to afford o-nitro (I), p-nitro (III), and o, p-dinitro (IV) derivertives.